1. Field of the Invention
The present invention relates to a sealing jig or fixture for sealing a cylinder inner peripheral surface which is a surface to be processed of a cylinder block of an engine, for example, at a time when treatment liquid is introduced to an inner peripheral surface of a cylinder and also relates to a plating treatment apparatus provided with such sealing jig for performing pre-plating or plating process to the cylinder inner peripheral surface.
2. Related Art
Conventionally, there is known a method for sealing a cylinder inner peripheral surface of a cylinder block in an apparatus for performing surface treatment such as plating treatment on the cylinder inner peripheral surface by introducing treatment liquid to the cylinder inner peripheral surface.
In a surface treatment apparatus described, for example, in Japanese Patent Application Laid-Open Publication No. 8-199390, diameter of a cylinder is completely expanded by repeating an operation of expanding the diameter of a sealing member and an operation of moving the entire sealing jig including the sealing member within the cylinder, and thereafter, the sealing operation is performed to the cylinder inner peripheral surface.
Furthermore, Japanese Patent Application Laid-Open Publication No. 8-144082 discloses a surface treatment apparatus in which an air tube is expanded so as to contact the cylinder inner peripheral surface, thereby sealing the cylinder inner peripheral surface.
However, the surface treatment apparatus described in Japanese Patent Application Laid-Open Publication No. 8-199390 has the following drawbacks. That is, when some failure occurs in adjustment of an expanding amount of a sealing member or adjustment of a moving amount of a sealing jig, the cylinder inner peripheral surface to be processed may be damaged, or sealing position with respect to the cylinder inner peripheral surface may be deviated, thus lowering sealing position accuracy.
In the surface treatment apparatus described in Japanese Application Laid-Open Publication No. 8-144082, it may become impossible to control a shape or sealing position of the air tube during the expansion because of insufficient positioning of the air tube. Accordingly, in this case, the sealing position accuracy of the cylinder inner peripheral surface may be insufficient.